Universal portable artificial kidney for hemodialysis and peritoneal dialysis

ABSTRACT

Methods, systems, and kits are provided for performing hemodialysis, hemodiafiltration, and peritoneal dialysis on a portable machine suitable for both clinical and home use. Peritoneal dialysate can be flowed into and out of the peritoneal cavity, and can also be regenerated within the system, without the need for introducing fresh dialysate. Common hardware and software can be utilized for both peritoneal dialysis and other forms of dialysis such as hemodialysis, hemofiltration, and hemodiafiltration, allowing for facile transition between different dialysis modes using the same dialysis machine.

FIELD

The present invention relates to kidney replacement dialysis and inparticular to materials and methods for performing peritoneal dialysis,as well as other modes of dialysis.

BACKGROUND OF THE INVENTION

Dialysis is an important treatment regimen for a variety of chronicdiseases. Dialysis to support a patient, whose renal function hasdecreased to the point where the kidneys no longer sufficientlyfunction, is well known. To meet the need for regular care, patientsoften travel to hospitals or dialysis centers. A nurse or patient caretechnician usually oversees dialysis treatment sessions at such centers.

With the advent of more affordable equipment, home dialysis isincreasingly an option for many dialysis patients, who find it offersthem greater privacy, flexibility of scheduling, and overall comfort.Home provision of hemodialysis can also be advantageous to health careproviders, because it does not require the nursing, equipment, andoverhead costs of standard in-center care. Government and privateinsurers also stand to benefit, because home hemodialysis tends to lowercoverage costs over the long term.

Two principal dialysis methods are utilized, hemodialysis, andperitoneal dialysis. In hemodialysis, the patient's blood is passedthrough an artificial kidney dialysis machine. A membrane in the machineacts as an artificial kidney for cleansing the blood. Extracorporealtreatment usually involves special machinery and a visit to a center,such as a hospital or an out-patient facility, where the treatment isperformed.

To overcome some of the disadvantages associated with hemodialysis,peritoneal dialysis was developed. Peritoneal dialysis is a medicalprocedure for removing toxins from the blood and takes advantage of thesemi-permeable membrane surrounding the walls of the abdomen orperitoneal cavity. During a peritoneal procedure, a solution isintroduced into the patient's abdomen, where it remains for up toseveral hours, removing blood toxins via osmotic transfer through theperitoneal membrane. At completion of the procedure, the solution isdrained from the body along with the toxins. In continuous ambulatoryperitoneal dialysis, a dialysis solution is introduced into theperitoneal cavity utilizing a catheter, normally placed into position bya surgical placement physician. An exchange of solutes between thedialysate and the blood is achieved by diffusion.

During the course of kidney disease, the needs and capabilities of apatient can change with respect to dialysis. While at times hemodialysismay be the appropriate treatment, at other times peritoneal dialysis maybe the best treatment. For example, the peritoneum of a patientundergoing peritoneal dialysis may degenerate overtime so that it can nolonger serve as a sufficient membrane for discharging toxins, solutes,and excess fluids. The patient would then likely need to be switched tohemodialysis if kidney transplantation is not available. For greaterflexibility and cost-savings, it would be advantageous to be able to usea common machine to perform hemodialysis or peritoneal dialysis,depending on the patient's dialysis requirements. Accordingly, there isa need for materials and methods for utilizing a dialysis machineinterchangeably between a peritoneal dialysis mode and a hemodialysismode.

SUMMARY OF THE PRESENT INVENTION

A feature of the present invention is to provide methods andcorresponding systems for carrying out peritoneal dialysis, which arealso compatible with hemodialysis, hemofiltration, andhemodiafiltration.

Another feature of the present invention is to provide methods andcorresponding systems for performing peritoneal dialysis, which allowfor transition between different modes of dialysis using a commondialysis machine.

Yet another feature of the present invention is to provide methods andcorresponding systems that enable the performance of both peritonealdialysis and associated dialysate regeneration.

Additional features and advantages of the present invention will be setforth in part in the description that follows, and in part will beapparent from the description, or may be learned by practice of thepresent invention. The objectives and other advantages of the presentinvention will be realized and attained by means of the elements andcombinations particularly pointed out in the description below andappended claims.

To achieve these and other advantages, and in accordance with thepurposes of the present invention, as embodied and broadly describedherein, the present invention relates to a method of performingperitoneal dialysis. Dialysate can be flowed through a manifold along afirst flow path and into a dialysate reservoir. The dialysate can beweighed in the dialysate reservoir. The dialysate can be flowed out ofthe reservoir, through the manifold along a second flow path, and into aperitoneal cavity. The dialysate can be flowed out of the peritonealcavity, through the manifold along a third flow path, and into a drainreservoir. The dialysate can be weighed in the drain reservoir. Thedialysate can be flowed out of the drain reservoir and through themanifold along a fourth flow path.

Peritoneal dialysis systems configured to carry out the methods of thepresent invention are also part of the present invention. For example, aperitoneal dialysis system is provided that can include one or more of amanifold, a dialysis machine in operable communication with the manifoldand configured to pump the dialysate through the first, second, third,and fourth flow paths, a dialysate reservoir in fluid communication withthe manifold, a drain reservoir in fluid communication with themanifold, a scale configured to weigh at least one of the dialysatereservoir and the drain reservoir, and a heater configured to heatdialysate in the dialysate reservoir. Kits for carrying out the dialysismethods are provided by the present invention, which can include one ormore components for carrying out the dialysis methods and/or forming thedialysis systems.

In accordance with the present invention, another method of performingperitoneal dialysis is provided. Dialysate can be flowed in a dialysatecircuit through a manifold along a first flow path that includes asorbent cartridge, and into a dialysate reservoir. The dialysate can beflowed in the dialysate circuit, out of the dialysate reservoir, andthrough the manifold along a second flow path. The dialysate can beflowed from the second flow path, across at least one filter, and into aperitoneum circuit. The dialysate in the peritoneum circuit can beflowed into a peritoneal cavity. The dialysate can be flowed out of theperitoneal circuit through the peritoneum circuit, across the filter,and back into the dialysate circuit. The dialysate can be flowed throughthe manifold, along a third flow path that includes the sorbentcartridge, and back into the dialysate reservoir.

In accordance with the present invention, a further method of performingperitoneal dialysis is provided. A first dialysate can be flowed in aperitoneum circuit along a first flow path through a manifold. A seconddialysate can be flowed in a regeneration circuit along a second flowpath through the manifold and a sorbent cartridge, and into a dialysatereservoir. The second dialysate can be flowed out of the dialysatereservoir along a third flow path through a first lumen of a dialyzer.The first dialysate can be flowed through a second lumen of thedialyzer, which is separated from the first lumen by at least onesemipermeable membrane. The first dialysate can be flowed into aperitoneal cavity. The first dialysate can be flowed out of theperitoneal cavity. The present invention provides methods of, andcomponents, machines, and systems for performing hemodialysis,hemofiltration, and hemodiafiltration, as well as peritoneal dialysis.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are intended to provide a further explanation of the presentinvention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this application, illustrate some of the embodiments of thepresent invention, and together with the description serve to explainthe principles of the present invention.

FIG. 1 is a front view of a dialysis system in accordance with thepresent invention.

FIG. 2 is a right perspective view a dialysis system in accordance withthe present invention, showing the modularity of the system.

FIG. 3 is a left view of a dialysis system in accordance with thepresent invention, with the door open to show a manifold engaged withthe system.

FIG. 4 is a front view of a manifold in accordance with the presentinvention.

FIG. 5 is a left, perspective, close-up view of a dialysis system inaccordance with the present invention, with the door open.

FIG. 6 is a schematic circuit diagram of a hemodialysis system inaccordance with the present invention.

FIG. 7 is a schematic flow diagram corresponding to the schematiccircuit diagram shown in FIG. 6.

FIG. 8 is a schematic circuit diagram of a peritoneal dialysis system inaccordance with the present invention.

FIG. 9 is a schematic flow diagram corresponding to the schematiccircuit diagram shown in FIG. 8.

FIG. 10 is a schematic circuit diagram of a peritoneal dialysis systemin accordance with the present invention.

FIG. 11 is a schematic flow diagram corresponding to the schematiccircuit diagram shown in FIG. 10.

FIG. 12 is a schematic circuit diagram of a peritoneal dialysis systemin accordance with the present invention.

FIG. 13 is a schematic flow diagram corresponding to the schematiccircuit diagram shown in FIG. 12.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

In accordance with the present invention, a universal system is providedthat can be used for hemodialysis or peritoneal dialysis. Methods ofperforming hemodialysis and peritoneal dialysis are also provided. Inthe method of performing peritoneal dialysis, dialysate can be flowedthrough a manifold along a first flow path and into a dialysatereservoir. The dialysate can be weighed in the dialysate reservoir. Thedialysate can be flowed out of the reservoir, along a second flow paththrough the manifold, and into a peritoneal cavity. The dialysate canhave any suitable dwell time in the peritoneal cavity, for example, lessthan about 5.0 minutes, from about 5.0 minutes to about 5.0 days, fromabout 30 minutes to about 2.0 days, from about 1.0 hour to about 1.0day, from about 2.0 hours to about 18 hours, from about 3.0 hours toabout 16 hours, from about 4.0 hours to about 12 hours, from about 6.0hours to about 10 hours, or for any other intervening time span. Thedialysate can be flowed out of the peritoneal cavity, along a third flowpath through the manifold, and into a drain reservoir. The dialysate canbe weighed in the drain reservoir. The dialysate can be flowed out ofthe drain reservoir and along a fourth flow path through the manifold.The dialysis methods of the present invention can be performedcontinuously or at prescribed intervals, which may be variable orconstant. For example, dialysis sessions can be separated by about 30minutes, by about 1.0 hour, by about 3.0 hours, by about 6.0 hours, byabout 12 hours, by about 18 hours, by about 1.0 day, by about 2.0 days,by about 3.0 days, by about 4.0 days, by about 1.0 week, or by about 2.0weeks or more. The dialysate can be heated in the dialysate reservoirusing one or more heater and thermistor. The dialysate reservoir and thedrain reservoir can be weighed using a common scale or separated scales.At least one of ultrafiltration volume and ultrafiltration rate can bedetermined based on a difference of the weights obtained from theweighing the clean dialysate in the dialysate reservoir and weighing thewaste dialysate in the drain reservoir.

The dialysate in the system can be flowed actively, passively, or by acombination thereof. A passive flow can be achieved by using gravityand/or a pressure differential. An active flow can be achieved by usingone or more pump of any suitable design. Accordingly, the dialysate canbe flowed by using at least one pump. The at least one pump can includeat least one peristaltic pump, at least one positive displacement pump,at least one negative displacement pump, at least one diaphragm pump, animpeller, a pumping chamber, or any combination thereof. The at leastone pump can include a first pump configured to control dialysate flowin one of the flow paths and a second pump configured to controldialysate in another of the flow paths. The at least one pump caninclude a pump configured to control dialysate flow in more than one ofthe flow paths. The pump can be configured to run in either direction.The flow paths described herein can include flow in one direction, flowin an opposite direction, flow in either direction, or flow in bothdirections along a given flow path.

Any of the methods of the present invention can include measurement ofany parameter, for example, pressure, temperature, conductivity, pH,solute concentration, solvent concentration, microorganisms, toxins, andthe like. Any of the methods, machines, and systems of the presentinvention can include one or more elements for controlling one or moreof such parameters. The methods can include detecting a condition, forexample, the presence of air in the system, or leaks into or out of thesystem. For example, a pressure of the dialysate can be measured in atleast one of the second and third flow paths. The flow of dialysate intoand/or out of the peritoneal cavity can be adjusted to control thedialysate pressure and keep it below a pre-determined value, forexample, a value determined to be deleterious to the peritoneum.

The methods of the invention can be repeated any desired number oftimes, for example, in accordance with a particular dialysisprescription, to achieve a desired result. Desired results can include,for example, removal of a particular amount or percentage of toxins,and/or an exchange of solvent. The method can be repeated by flowing afresh supply of dialysate through the first flow path after flowing thedialysate through the fourth flow path. The method can include flowing afresh supply of dialysate through a fifth flow path and into thedialysate reservoir after flowing the dialysate through the fourth flowpath. The fresh supply of dialysate can differ in composition from thedialysate originally flowed through the manifold and into the dialysatereservoir. Such a difference in composition is consistent with thepractice in the art of a “last bag” approach in peritoneal dialysis, forexample, the use of a different dialysate formulation after a number ofcycles of dialysate flow in and out of the peritoneal cavity.

Any method of the present invention can be practiced using any suitabledialysis machine. Accordingly, the method can further include engagingthe manifold with a dialysis machine configured to carry out the method.The manifold can be placed in fluid communication with a supply ofdialysate. The method can further include attaching one or more otherdisposables to the dialysis machine, such as dialyzers, filters, plastictubing, sorbent cartridges, reservoir liners, ammonia sensors, primingfluid sources, electrolyte sources, osmotic agent sources, and the like.The manifold and one or more of these other disposables can be providedpreassembled, partially or completely, for example, as part of a kit.The components in the kit can be preassembled (connected), separate, orboth. Components can be coded, for example, using colors, letters,numbers, barcodes, RFID tags, or a combination thereof, to aid in theassembly of the components with a dialysis machine to form a dialysissystem. One or more components of the kit can be disposable and/orreusable.

Any suitable manifold can be used in accordance with the methods andsystems of the present invention. The manifold can be disposable and/orreusable. The manifold can be provided with any suitable or desireddesign that permits a method of the present invention to be performed.The manifold can be provided with a shape or other physical or geometricparameter that allows the manifold to engage a suitable dialysismachine, for example, in only one orientation. For example, the manifoldcan have an H-shaped or I-shaped design. Such a design can include firstand second transoms connected by a central trunk. The first transom canhave a first edge, and second and third edges that are substantiallyparallel to the first edge. The trunk can be substantially perpendicularand adjacent to the first transom. The second transom can have a fourthedge, and fifth and sixth edges that are substantially parallel to thefirst, second, and third edges. The second transom can be substantiallyperpendicular and adjacent to the trunk and substantially parallel tothe first transom. One or more conduits, that is, internal passageways,can be integrated into the manifold along with one or more ports toallow for fluid communication with other conduits or fluid passagewaysexternal to the manifold. The manifold can be provided with any suitablenumber of conduits, that is, interior passage ways, for carrying out themethod. For example, the manifold can include at least four manifoldconduits and each flow path can include at least one manifold conduitnot included by the other three flow paths. The manifold can contain atleast two manifold conduits and at least two of the four flow paths caninclude a common manifold conduit. Any desirable type or number ofadditional elements can be included in the manifold, for example, pumptubes, valves, pressure chambers, pressure sensors, flow rate sensors,conductivity sensors, air detectors, blood detectors, toxin detectors,actuators, thermistors, heaters, conductivity meters, pH meters,components thereof, and combinations thereof.

U.S. Patent Application Publication Nos. US 2012/0280154 A1 and US2010/0179464 A1, which are incorporated herein by reference in theirentireties, describe valves and other elements that can be used inaccordance with the present invention. US 2012/0204968 A1, which isincorporated herein by reference in its entirety, describes primingmethods and other elements that can be used in accordance with thepresent invention. US 2012/0103885 A1, US 2012/0090706 A1, US2010/0116740 A1, and US 2009/0173682 A1, which are incorporated hereinby reference in their entireties, describe manifolds, ultrafiltrationcontrol means, and other elements that can be used in accordance withthe present invention. US 2010/0331754 A1, 2009/0101577 A1, and US2009/0076434 A1, which are incorporated herein by reference in theirentireties, describe pressure measurements, volume control,ultrafiltration control, and other elements that can be used inaccordance with the present invention. US 2010/0252490 A1, which isincorporated herein by reference in its entirety, describes a dialysatereservoir and other elements that can be used in accordance with thepresent invention. US 2010/0234786 A1, which is incorporated herein byreference in its entirety, describes a disconnection monitor and otherelements that can be used in accordance with the present invention. US2010/0184198 A1, which is incorporated herein by reference in itsentirety, describes a method of ammonia removal and other elements thatcan be used in accordance with the present invention. US 2011/0315611A1, US 2011/0054378 A1, US 2010/0140149 A1, and US 2009/0101552 A1,which are incorporated herein by reference in their entireties, describea manifold, dialysis machine, dialysis system, and other elements thatcan be used in accordance with the present invention. US 2012/0073365A1, US 2010/0116048 A1, and US 2009/0114037 A1, which are incorporatedherein by reference in their entireties, describe flow meters and otherelements that can be used in accordance with the present invention.

Peritoneal dialysis systems configured to carry out the methods of thepresent invention are also part of the present invention. For example, aperitoneal dialysis system is provided that can include one or more of amanifold, a dialysis machine in operable communication with the manifoldand configured to pump the dialysate through the first, second, third,and fourth flow paths, a dialysate reservoir in fluid communication withthe manifold, a drain reservoir in fluid communication with themanifold, a scale configured to weigh at least one of the dialysatereservoir and the drain reservoir, and a heater configured to heatdialysate in the dialysate reservoir. Kits for carrying out the dialysismethods are provided by the present invention, which can include one ormore components for carrying out the dialysis methods and forming thedialysis systems.

Another method of performing peritoneal dialysis is provided by thepresent invention, wherein dialysate can be flowed in a dialysatecircuit through a manifold along a first flow path that includes asorbent cartridge, and into a dialysate reservoir. The dialysate can beflowed in the dialysate circuit out of the dialysate reservoir andthrough the manifold along a second flow path. The dialysate can beflowed from the second flow path, across at least one filter, and into aperitoneum circuit. The dialysate in the peritoneum circuit can beflowed into a peritoneal cavity. The dialysate can be maintained in theperitoneal cavity for a suitable dwell time. The dialysate can be flowedout of the peritoneal cavity through the peritoneum circuit, across thefilter, and back into the dialysate circuit. The dialysate can be flowedthrough the manifold along a third flow path that includes the sorbentcartridge, and back into the dialysate reservoir. Any suitable filtercan be used. The filter can be a dialyzer and/or a dialysis membrane.The filter can be a bacterial filter. For example, any of the bacterialfilters described in U.S. Pat. Nos. 4,311,587, 4,347,136, 4,568,366,5,868,933, U.S. Pat. No. 6,565,749 B2, U.S. Pat. No. 6,989,101B2, U.S.Pat. No. 7,303,683 B2, U.S. Pat. No. 7,614,506 B2, U.S. Pat. No.7,615,152 B2, and U.S. Pat. No. 7,922,008 B2 can be used, and all ofthese patents are incorporated herein by reference in their entireties.The bacterial filters described in U.S. Patent Application PublicationsNos. 2001/0037964 A1, US 2003/0000884 A1, US 2003/0098276 A1, US2004/0164006, US 2005/0000883 A1, US 2007/0278141 A1, US 2008/0164214A1, and US 2009/0188854 A1 can be used, all of these publications areincorporated herein by reference in their entireties.

The method can include heating the dialysate in the dialysate reservoir.The method can include weighing the dialysate in the reservoir, forexample, before the dialysate is flowed into the peritoneum, after thedialysate is returned to the dialysate reservoir, or both. At least oneof ultrafiltration volume and ultrafiltration rate can be determinedbased on a difference of weights obtained from the weighing thedialysate before and after the dialysate has resided in the peritonealcavity.

Any suitable manifold described herein or otherwise known or compatiblecan be used in the methods of the present invention. The manifold cancontain at least three manifold conduits and each flow path can includeat least one manifold conduit not included by the other three flowpaths. The manifold can contain at least two manifold conduits and atleast two of the three flow paths can share a common manifold conduit.The third flow path can share at least one common conduit with both thefirst and second flow paths, and the first and second flow paths caninclude no conduits in common.

The dialysate can be flowed using at least one pump. The at least onepump can include at least one peristaltic pump, another pump describedherein, or any other suitable pump. The at least one pump can include apump configured to control dialysate flow in more than one of the flowpaths. The method can include measuring for the presence of air, and ifair is detected, can trigger an alarm or other warning. The pressure ofthe dialysate can be measured in at least one of the second and thirdflow paths. The flow of dialysate into and/or out of the peritonealcavity can be adjusted to control the dialysate pressure to keep itmaintained below a pre-determined value. The method can be repeated byflowing dialysate from the dialysate reservoir through the second flowpath after returning the dialysate through the third flow path to thedialysate reservoir. At least one filter can be used, for example, atleast one dialyzer, or any other filter known or described herein, orany filter compatible with the method. The flow of dialysate in thesecond flow path can be split between at least two different branchlines before passing across the at least one filter. Any suitablemanifold, machine, or system described herein, or otherwise known, orotherwise compatible, can be used to carry out the method. The manifoldcan be engaged with a dialysis machine configured to carry out themethod. The manifold can be placed in fluid communication with a supplyof dialysate.

A peritoneal dialysis system configured to perform the peritonealdialysis methods described herein, is provided. The system can containone or more of a manifold, a dialysis machine in operable communicationwith the manifold and configured to pump the dialysate through thefirst, second, and third flow paths, a dialysate reservoir in fluidcommunication with the manifold, a filter in fluid communication withthe manifold, a sorbent cartridge in fluid communication with themanifold, a scale configured to weigh the dialysate reservoir, and aheater configured to heat dialysate in the dialysate reservoir.

A further method of performing peritoneal dialysis is provided by thepresent invention. A first dialysate can be flowed in a peritoneumcircuit along a first flow path through a manifold. A second dialysatecan be flowed in a regeneration circuit through the manifold and sorbentcartridge along a second flow path, and into a dialysate reservoir. Thesecond dialysate can be flowed out of the dialysate reservoir along athird flow path through a first lumen of a dialyzer. The first dialysatecan be flowed through a second lumen of the dialyzer, separated from thefirst lumen by at least one semipermeable membrane. The first dialysatecan be flowed into a peritoneal cavity. The first dialysate can bemaintained in the peritoneal cavity for a suitable dwell time, and thenit can be flowed out of the peritoneal cavity.

The first and/or second dialysates can be heated in the dialysatereservoir. The first and second dialysates can be flowed using at leastone pump. For example, the at least one pump can include at least oneperistaltic pump, another pump described herein, or any other pumpcompatible with the methods and systems of the present invention. Thefirst dialysate can be pumped along the first flow path using a firstpump, the second dialysate can also be pumped along the second flow pathusing a second pump, and the second dialysate can be pumped along thethird flow path using a third pump. Electrolytes can be pumped into theregeneration circuit using a fourth pump. The method can includemeasuring for the presence of air, and triggering an alarm or otherwarning if air is detected. The method can include measuring a pressureof the first dialysate in the peritoneum circuit. The flow of the firstdialysate into and/or out of the peritoneal cavity can be adjusted tocontrol the dialysate pressure to keep it below a pre-determined value.The amount of dialysate added to and/or removed from the peritoneum canbe controlled using pressure transducers, in-line flow meters,non-evasive flow meters, or any combination thereof. The same or similardevices can be used for measurements. Examples of non-evasive flowmeters include Transonic™ flow meters available from Transonic Systems,Inc., Ithaca, N.Y.

The first dialysate can be flowed through the dialysate circuit throughthe sorbent cartridge and the manifold along a fourth flow path, andacross the at least one semipermeable membrane from the first lumen tothe second lumen and into the peritoneum circuit. The fourth flow pathcan include at least one filter located between the manifold and thefirst lumen. The at least one filter can include a second dialyzer. Thefirst, second, or any additional dialyzer can be chosen from anysuitable dialyzer compatible with the methods, machines, and systems ofthe present invention. A polysulfone dialyzer can be used. For example,the dialyzer can be an F180PSD, an F180NRE, an Optiflux®, a Hemaflow™,or an Ultraflux dialyzer available from Fresenius Medical Care NorthAmerica, Waltham, Mass. The dialyzers described in U.S. Pat. Nos.4,141,836, 4,172,794, 4,261,830, 5,882,516, U.S. Pat. No. 6,802,821B2,U.S. Pat. No. 6,911,007 B2, U.S. Pat. No. 8,202,428 B2, and U.S. Pat.No. 8,303,807 B2 can be used, all of which patents are incorporatedherein by reference in their entireties. The dialyzers described in U.S.Patent Application Publications Nos. US 2005/0236330 A1, US 2009/007862A1, US 2009/0223880 A1, US 2012/0172736 A1, and US 2013/0004593 A1 canbe used, and all of these publications are incorporated herein byreference in their entireties. An ion-rejecting dialyzer membrane can beused, which can reduce or eliminate the need for added electrolytes and,accordingly, increase portability.

The second dialysate can be drained from the regeneration circuit alonga fifth flow path. The first dialysate can be flowed across thesemipermeable membrane along a sixth flow path from the second lumen tothe first lumen, to transfer the first dialysate out of the peritoneumcircuit and into the dialysate circuit. The weight of the firstdialysate can then be measured. The weight of the first dialysatemeasured after flowing the first dialysate out of the peritoneum circuitand into dialysate circuit can be compared with an earlier measuredweight of the first dialysate to determine at least one ofultrafiltration volume and ultrafiltration rate. The first dialysate canbe flowed along a seventh flow path back across the semipermeablemembrane from the first lumen to the second lumen, out of theregeneration circuit, and into the peritoneum circuit. The seventh flowpath can contain at least one filter located between the manifold andthe first lumen. The regeneration circuit can be filled with freshdialysate to reform the second dialysate.

The manifold can be engaged with a dialysis machine configured to carryout the method. The manifold can be placed in fluid communication with asupply of dialysate. Any suitable manifold can be used in accordancewith the present invention. A peritoneal dialysis system configured toperform the method is also provided in accordance with the presentinvention. The system can include one or more of a manifold, a dialysismachine in operable communication with the manifold and configured topump the dialysate through the first, second, and third flow paths, adialysate reservoir in fluid communication with the manifold, a filterin fluid communication with the manifold, a sorbent cartridge in fluidcommunication with the manifold, a scale configured to weigh thedialysate reservoir, and a heater configured to heat dialysate in thedialysate reservoir.

A sorbent cartridge for use in the present invention can contain one ormore of activated carbon, urease, zirconium phosphate, zirconiumcarbonate, and zirconium oxide. Any suitable sorbent cartridge can beused. For example, a HISORB® or HISORB®+sorbent cartridge available fromRenal Solutions, Inc. of Warrendale, Pa. can be used. The sorbents andsorbent cartridges described in U.S. Pat. Nos. 3,989,622, 4,190,047,4,213,859, 4,247,393, 4,661,246, 5,277,820, 5,536,412, 5,919,369,5,944,684, U.S. Pat. No. 6,348,162 B1, U.S. Pat. No. 6,960,179 B2, U.S.Pat. No. 7,033,498 B2, U.S. Pat. No. 7,169,303 B2, U.S. Pat. No.7,208,092 B2, U.S. Pat. No. 7,736,507 B2, U.S. Pat. No. 7,867,214 B2,U.S. Pat. No. 7,922,686 B2, U.S. Pat. No. 7,922,911 B2, B2, U.S. Pat.No. 8,080,161 B2, U.S. Pat. No. 8,096,969 B2, U.S. Pat. No. 8,105,487B2, U.S. Pat. No. 8,187,250 B2, U.S. Pat. No. 8,220,643 B2, and U.S.Pat. No. 8,357,113 B2 can be used, and all of these patents areincorporated herein by reference in their entireties. Sorbents andsorbent cartridges described in U.S. Patent Application PublicationsNos. US 2002/0112609 A1, US 20030097086 A1, US 20030114787 A1, US2004/0019312 A1, US 2004/0019320 A1, US 2004/0050789 A1, US 2004/0082903A1, US 2005/0006296 A1, US 2005/0131332 A1, US 2007/0158267 A1, US2007/0179431 A1, US 2007/0213665 A1, US 2009/0120864 A1, US 2009/0127193A1, US 2009/0264812 A1, US 2009/0314707 A1, US 2010/0010429 A1, US2010/0010430 A1, US 2010/0078387 A1, US 2010/0100027 A1, US 2010/0114012A1, US 2010/0217181 A1, US 2010/0230346 A1, US 2010/0312172 A1, US2010/0312174 A1, US 2010/0314314 A1, US 2011/0017665 A1, US 2011/0155667A1, US 2011/0171713 A1, US 2011/0184340 A1, US 2011/0272337 A1, US20110297593 A1, US 2011/0303588 A1, US 2011/0303590 A1, US 20120248017A1, US 2011/0315611 A1, US A1, US 2012/0271227 A1, or US 2013/0008852 A1can be used, and all of these publications are incorporated herein byreference in their entireties. Dialysis regeneration can be achievedusing other techniques instead of, or in addition to, sorbent-basedtechniques, to remove toxins or other species. For example,electrodialysis can be used as described in U.S. Patent ApplicationPublications Nos. US 2012/0273354 A1 and US 2012/0220926 A1, which areincorporated herein by reference in their entireties.

The methods, manifolds, machines, and systems of the present inventioncan be used or modified for use in performing hemodialysis,hemofiltration, hemodiafiltration, peritoneal dialysis, or anycombination thereof, while still falling within the scope of the presentinvention. For a peritoneal dialysis mode, the same manifold can beutilized that is used in a hemodialysis mode, with or withoutmodification of tubing and/or other disposables attached to themanifold. A reservoir bag can be used in, or as, the dialysis reservoir.In addition to the reservoir bag, a drain bag can be used, for example,as the drain reservoir or part thereof. The drain bag can be placedwithin, alongside, or at a different location from the reservoir bag.Both the reservoir bag and the drain bag can be weighed on the samescale, or on separate scales, in order to determine the ultrafiltratevolume from a patient, prior to sending the contents to a drain.Peritoneal dialysate supplied from dialysate supply bags can be pumpedinto the reservoir using a pump segment used for pumping blood duringhemodialysis. An appropriate fill volume of peritoneal dialysate can beweighed by the scale and heated by the heater. An air sensor can be usedto help assure that air is not being introduced from the dialysatesupply bags. Once warmed to an appropriate temperature, the dialysatecan be pumped out of the reservoir bag, via a pump and bypass valve, andto the patient, via the manifold. Upon completion of the dwell cycle inthe patient, dialysate fluid can be pumped from the patient back throughthe manifold, using a pump and a valve, and into the drain bag to beweighed. Upon recording the weight, the pump can be reversed and thedialysate can be pumped to the drain via the manifold.

Pressure sensors located at the outlet of the second dialysate pump andat the inlet of a pump can be used to help assure that maximum tolerablepressures within the peritoneum of the patient are not exceeded.Dialysate from a last bag can be pulled in, through the manifold, viatwo valves using the same pump or a different pump, and then heated inthe reservoir bag. The reservoir bag can be emptied before pulling thedialysate from the last bag, by pumping out any remaining dialysatethrough valves, to minimize any mixing of dialysates.

The systems of the present invention can be used to regenerateperitoneal dialysate. A pump tube normally used for engaging a pumpduring hemodialysis need not be used and one end of a dialyzer can beclosed off so that the dialysate infused into and out of a patient gothrough the dialyzer membrane to maintain the sterility of thedialysate. Peritoneal dialysate can be drawn into the system from supplybags, through the manifold, using a pump where a fill/drain line islocated. The peritoneal dialysate can be pushed through a sorbentcartridge, where calcium, magnesium, and potassium can be removed. Afterexiting the sorbent cartridge, the peritoneal dialysate can enter thereservoir bag where it is weighed and warmed. To infuse a first fillinto the patient, a pump can be used to draw the peritoneal dialysateout of the reservoir. The correct amount of electrolytes, for example,calcium, magnesium, and potassium, can be infused into the peritonealdialysate using a pump to pull electrolytes from an electrolyte source.A pump can then pump the fortified peritoneal dialysate through valvesin the manifold and across a dialyzer membrane or other filter. Asuitable manifold valve can be closed at this time to assure that theperitoneal dialysate goes into the top of the dialyzer, to help maximizeuse of the full capacity of the membranes, and into the peritonealcavity. Pressure sensors and air sensors in the line running from/to thepatient can be activated along with the added safety of a pinch valvefor possible failures. Upon completion of a dwell period, spentperitoneal dialysate can be pumped out of the cavity peritoneal using apump. The spent peritoneal dialysate is then flowed across asemipermeable membrane, through the sorbent cartridge, and back into thereservoir bag for the next fill. Ultrafiltrate volume can be determinedby how much fluid gets returned to the reservoir, which is weighed by ascale. Depending upon the sterility of the solution going to thepatient, two dialyzers, and/or other filters, can be linked together.Instead of, or in addition to, the use of prepared (for example, bagged)peritoneal dialysate, tap water can be used for the initial solutionthat is run through the sorbent cartridge and subsequently fortifiedwith electrolytes. A pump can be used to infuse glucose if needed. Alast bag of peritoneal dialysate can be used.

The flow path of a peritoneal mode can be configured similar to the flowpath of a hemodialysis mode. A secondary dialyzer can be utilized in thecircuit for sterile protection. Water can be pulled up through afill/drain valve and processed through a sorbent cartridge. The watercan contain sodium in an amount that depends on how much urea is to beprocessed. The initial fluid can then be supplemented with theappropriate amount of electrolytes, for example, calcium, magnesium, andpotassium. A fill volume can be infused into the patient's peritoneum byusing appropriate valves and pumps and closing, stopping, or disablingothers. Spent peritoneal dialysate can then be recirculated at a lowflow rate via a pump through the primary dialyzer while other pumpscirculate peritoneal dialysate through the secondary dialyzer and theprimary dialyzer at a zero ultrafiltration rate. On the peritoneum sideof the system, the patient connections can be connected to a dual lumencatheter for continuous recirculation through the peritoneum via a pumpthat would be akin to the blood pump during a hemodialysis mode. A pumpthat would be a heparin pump in a hemodialysis configuration can be usedto replenish glucose levels in the dialysate on the peritoneum side ofthe system.

The ultrafiltrate volume can be determined using appropriate valves andpumps and closing, stopping, or disabling others to periodically emptythe peritoneal dialysate from the peritoneum into a reservoiroperatively associated with a scale. This procedure can be performedwhile monitoring the pressure sensors in the peritoneum circuit. Thedifference between the initially infused volume of peritoneal dialysateand the measured volume of peritoneal dialysate post-drain can beequated with the ultrafiltrate volume. A pump can subsequently be usedto re-infuse the initial fill volume back into the peritoneum and theprocess of recirculation can continue.

The present invention can use manifolds, disposables, dialysis machines,dialysis systems, methods or any other aspect of dialysis as describedin U.S. Patent Application Publications Nos. US 2012/0280154 A1, US2012/0204968 A1, US 2012/0103885 A1, US 2012/0090706 A1, US 2012/0073365A1, US 2011/0315611 A1, US 2011/0054378 A1, US 2010/0331754 A1, US2010/0252490 A1, US 2010/234786 A1, US 2010/0184198 A1, US 2010/0179464A1, US 2010/0140149 A1, US 2010/0116740 A1, US 2010/0116048 A1, US2009/0173682 A1, US 2009/0114037 A1, US 2009/0101577 A1, US 2009/0101552A1, US 2009/0076434 A1, which are all incorporated herein by referencein their entireties.

Referring to FIGS. 1, 2, and 3, the dialysis system 100, 200 includes atop unit 101, 201 that is detachably affixed to a base 102, 202. Baseunit 102, 202 contains a reservoir 122, 222 for fluid storage,measurement, and monitoring. Top unit 101, 201, also referred to as themain unit or controller unit, includes a graphical user interface 114,214, a pumping unit, and a door 110, 210 having a power lock. To a firstside of top unit 101, 201, is a clasp 105 used to detachably affix adialyzer 103, 313. Also to a side of top unit 101, 201, is a sorbentcartridge locking base 104, 204, 318, that is used to detachably affix asorbent cartridge 107, 317. Clasp 105, hemofilter 103, 315, sorbentcartridge locking base 104, 204, 318 and sorbent cartridge 107, 317 canbe positioned on the same side of top unit 101, as shown in FIG. 3, oron different sides or at different positions. In either case, base unit102, 202, 302 can have a sufficiently larger top surface area relativeto the top unit such that shelves can be formed on either side of thetop unit to hold the sorbent cartridge, to hold an infusate jar, tocapture any spillage, and/or to channel any leaks into a leak detector.With reference to FIG. 3, a door 319 is shown in an open position toreveal a manifold 320 mounted to the top unit 301. A handle 311 can beprovided on top unit 301. The system configurations shown in FIGS. 1, 2,and 3 are exemplary and not limiting. For example, as shown in FIG. 3,top unit 301 can be positioned on one side of base unit 302, as opposedto being centrally positioned on top of base unit 302. Further detailsof suitable dialysis machines and components thereof, which can be usedto carry out the methods of the present invention and form the systemsof the present invention, are described, for example, in U.S. PatentApplication Publication No. US 2011/0315611 A1, which is incorporatedherein by reference in its entirety.

With reference to FIG. 4, a manifold 410 can be provided that has acapital I-shaped body 412. Manifold body 412 can include a first transom414 and a second transom 416 that are joined together by a centralmember or trunk 418. Both transoms can have first and second armslocated on either side of trunk, for example, a first arm 420 can be ona left side of transom 414 and a second arm 422 can be on the right sideof transom 414. Similarly, third and fourth arms 424, 426 can be onrespective sides of second transom 416. First transom 414 can havefirst, second, and third edges 428, 430, and 432, respectively. Firstedge 428 spans first transom 414, and second edge 430 and third edge 432are along first arm 420 and second arm 422, respectively. Second transom416 can have fourth, fifth, and sixth edges, 434, 436, and 438,respectively. Fourth edge 434 spans second transom 416, and fifth edge436 and sixth edge 438 are along third arm 424 and fourth arm 426,respectively.

Various conduits can be located in manifold body 412 and can be in fluidcommunication with valves, pressure sensor chambers, and other elementswithin manifold body 412 as well as being in fluid communication withone or more manifold ports on manifold body 412. The manifold ports caninclude intra-manifold ports and external ports. The intra-manifoldports can be joined by one or more pumping tube, and the external portscan fluidly connect the manifold to other portions of the dialysismachine and to the patient, via tubes. The tubes can be flexible. Aflexible membrane or sheet can cover part of one or more sides of themanifold and can form part of the manifold body.

As depicted in FIG. 4, the external ports can be lettered from “A” to“M” (omitting “I”). The intra-manifold ports can be referred to byordinal numbers, for example, 440, 442, 444, 446, 448, 450, 452, and454. External ports A and B are shown along first edge 428 of firsttransom 414 and external ports C through M are arrayed along fourth edge434 of second transom 416. First and second intra-manifold ports 440,442 are arrayed along second edge 430 of first arm 420. Third and fourthintra-manifold ports 444, 446 are arrayed along third edge 432 of secondarm 422. Fifth and sixth intra-manifold ports 448, 450 are arrayed alongfifth edge 436 of third arm 424, and seventh and eighth intra-manifoldports 452, 454 are arrayed along sixth edge 438 of fourth arm 426. Afirst pumping tube 456 joins first and fifth intra-manifold ports 440,448, respectively. A second pumping tube 458 joins second and sixthintra-manifold ports, 442, 450, respectively. A third pumping tube 460joins third and seventh intra-manifold ports, 444, 452, fourth pumpingtube 462 joins the fourth and eighth intra-manifold ports 446, 454,respectively.

A first conduit 464 can extend from external port A to firstintra-manifold port 440 and can contain a first pressure sensor chamber466. A second conduit 468 can extend from fifth intra-manifold port 448to external port C. A third conduit 470 can branch off of second conduit468 and extend to external port D. A fourth conduit 472 can extendbetween external port F and external port G, and can contain a secondpressure sensor chamber 474. A fifth conduit 476 can extend fromexternal port J to a first multivalve 478. A sixth conduit 480 canextend from first multivalve 478 to the fourth intra-manifold port 446,and can contain a third pressure sensor chamber 482. A seventh conduit484 can extend from eighth intra-manifold port 454 to external port M,and can include a fourth pressure sensor chamber 486. An eighth conduit488 can extend from external port E to sixth intra-manifold port 450. Aninth conduit 490 can extend from second intra-manifold port 442 to asecond multivalve 492, and can include a fifth pressure sensor chamber494. A tenth conduit 496 can extend from second multivalve 492 toexternal port H. An eleventh conduit 498 can extend from external port Bto a third multivalve 500. A twelfth conduit 502 can connect thirdmultivalve 500 to first multivalve 478, and a thirteenth conduit 504 canconnect second and third multivalves 492, 500 respectively. A fourteenthconduit 506 can extend from external port L to seventh intra-manifoldport 452. A fifteenth conduit 508 can extend from third intra-manifoldport 444 to external port K. While certain conduits are described ascontaining a pressure sensor chamber, any conduit can contain any numberof pressure sensor chambers. Each pressure sensor chamber can beindependently covered by the flexible sheet and be aligned with apressure sensor on a dialysis machine housing to allow for pressuremeasurements of a fluid with a given conduit. The multivalves can alsobe covered by the flexible sheet and can be aligned with actuators on adialysis machine housing, the actuators being configured to control themultivalves and flow through the multivalves.

FIG. 5 is a partial view of a dialysis machine 520 in accordance withthe present invention. Dialysis machine 520 has a machine housing 522 towhich first and second hinges 524, 526, respectively, are mounted. Adoor 528 is, in turn, mounted to these hinges Door 528 is shown in anopen position in FIG. 5, but can be closed and secured with a door lockthat includes a door lock insert 530 attached to door 528, and a doorlock receptacle 532 disposed in machine housing 522. A manifoldreceptacle 534 is mounted on machine housing 522 and is configured toreceive a manifold, for example, manifold 410 shown in FIG. 4. First,second, third, and fourth peristaltic pumps 536, 538, 540, and 542,respectively, are inset in machine housing 522 and positioned to engagefirst, second, third, and fourth pump tubes or pump headers, forexample, pump tubes 456, 458, 460, and 462, shown in FIG. 4,respectively. First, second, third, and fourth pump shoes 544, 546, 548,and 550, respectively, are mounted on the inside of door 528 and areconfigured to press first, second, third, and fourth pump tubes of amanifold against first, second, third, and fourth peristaltic pumps 536,538, 540, and 542, respectively. A platen 552 is also mounted on theinside of door 528 and is configured to press a manifold, for example,manifold 410, shown in FIG. 4, into manifold receptacle 534.

First, second, third, fourth, and fifth pressure sensors 554, 556, 558,560, and 562, respectively, are positioned on machine housing 522 withinmanifold receptacle 534 to engage first, second, third, fourth, andfifth pressure sensor chambers 466, 474, 482, 486, and 494, shown inFIG. 4, respectively. A first set of valve actuators 564 is positionedin machine housing 522 within manifold receptacle 534, to engage firstmultivalve 478 shown in FIG. 4. A second set of valve actuators 566 ispositioned in machine housing 522 within manifold receptacle 534 toengage second multivalve 492 shown in FIG. 4. A third set of valveactuators 568 is positioned in machine housing 522 within manifoldreceptacle 534 to engage third multivalve 500 shown in FIG. 4. First andsecond air detectors 570, 572 are included in machine housing 522. Ablood leak detector 574, an occlusion detector 576, and a bloodlineclamp 578, are also included in machine housing 522.

FIG. 6 shows a schematic diagram of a hemodialysis system 610 that canutilize a suitable manifold, for example, manifold 410, the details ofwhich are shown in FIG. 4. External tubes, preferably flexible, are usedto connect the manifold via the external ports to other components ofthe dialysis system, such as a dialyzer 612, an anticoagulant source614, a saline source 616, an electrolyte source 618, a sorbent cartridge620, a dialysate source 622, and a dialysate reservoir 624.Collectively, the manifold, external tubes, and other dialysis systemcomponents can form one or more circuits, for example, an extracorporealblood circuit and a dialysate circuit. One can appreciate that a giventube can be made of one or more shorter tubes joined together by one ormore connectors.

As can be seen in FIG. 6, an extracorporeal blood circuit 626 isprovided in the hemodialysis system shown. A first external tube 628 canextend from the patient, for example, an artery of the patient, toexternal port C. A second external tube 630 can extend from externalport A to a first dialyzer port 632. A third external tube 634 canextend from a second dialyzer port 636 to external port G. A fourthexternal tube 638 can extend from external port F back to the patient,for example, to a vein of the patient. A fifth external tube 640 canconnect anti-coagulant source 614 to the extracorporeal blood circuit626, for example, at a first branch point 642 in second external tube630. A sixth external tube 644 can connect saline source 616 to externalport D.

With reference to FIGS. 4-6, blood can flow in extracorporeal bloodcircuit 626 in the following manner. The flow can be powered andcontrolled by first peristaltic pump 536, shown in FIG. 5, operativelyassociated with first pump tube 456, shown in FIG. 4. Blood can flowfrom the patient, for example, out of an artery, through first externaltube 628, through second conduit 468, first pump tube 456, through firstconduit 464, through second external tube 630, through dialyzer 612,through third external tube 634, through fourth conduit 472, throughfourth external tube 638, and back to the patient, for example, into avein of the patient. Anticoagulant can be supplied through fifthexternal tube 640 into extracorporeal blood circuit 626. A primingsequence can be used in extracorporeal blood circuit 626 by flowingsaline from saline source 616 through external tube 644 and thirdconduit 470 into extracorporeal blood circuit 626, for example, at alocation along second conduit 468. Flow in extracorporeal blood circuit626 is also shown in FIG. 7, which further depicts a pinch valve 573.

A dialysate circuit 646 can also form part of hemodialysis system 610. Aseventh external tube 648 can extend from a dialysate or water source622 to external port J. An eighth external tube 650 can extend fromexternal port M to a first sorbent cartridge port 652. A ninth externaltube 654 can extend from a second sorbent cartridge port 656 to anammonia sensor 658. A tenth external tube 660 can extend from ammoniasensor 658 to dialysate reservoir 624. An eleventh external tube 662 canextend from dialysate reservoir 624 to external port E. A twelfthexternal tube 664 can extend from external port H to a third dialyzerport 665. A thirteenth external tube 668 can extend from a fourthdialyzer port 670 to external port B. A fourteenth external tube 672 canextend from electrolyte source 618 to external valve port L. A fifteenthexternal tube 674 can extend from external port K to a second branchpoint 676 in eleventh external tube 662.

As can be seen in FIGS. 4-6, dialysate can flow through dialysatecircuit 646, which can be powered by second and fourth peristaltic pumps538, 542, respectively, shown in FIG. 5, which are in operativeassociation with second and fourth pump tubes 458, 462, respectively,shown in FIG. 4. Third peristaltic pump 540 can be in operativeassociation with third pump tube 460 to allow a flow of electrolytes toenter dialysate circuit 646. Dialysate, or water, can flow fromdialysate source 622 through seventh external tube 648, fifth conduit476, sixth conduit 480, fourth pump tube 462, seventh conduit 484,eighth external tube 650, sorbent cartridge 620, ninth external tube654, ammonia sensor 658, tenth external tube 660, dialysate reservoir624, eleventh external tube 662, eighth conduit 488, second pump tube458, ninth conduit 490, tenth conduit 496, twelfth external tube 664,dialyzer 612, thirteenth external tube 668, eleventh conduit 498,twelfth conduit 502, and back to sixth conduit 480, to completedialysate circuit 646. Electrolytes can flow through fourteenth externaltube 672, fourteenth conduit 506, pump tube 460, fifteen conduit 508,and into dialysis circuit 646, for example, at second branch point 676along eleventh external tube 662. Dialysate circuit 646 is also shown inFIG. 7, which further depicts a scale 623 and a heater/thermistorassembly 625, as well as a level detector 619 for measuring the amountof electrolyte solution in electrolyte source 618. In FIG. 7, the samereference numbers used in FIGS. 4-6 depict the same features.

FIG. 8 is a schematic circuit diagram of a peritoneal dialysis system810 in accordance with the present invention. FIG. 9 is a schematic flowdiagram of peritoneal dialysis system 810. Various components referredto in this description of peritoneal dialysis system 810 are shown inFIGS. 4-6 and discussed above, and the same reference numbers depict thesame features. Dialysate can be pumped using first peristaltic pump 536into a dialysate circuit 812 from an appropriate peritoneal dialysatesource, for example, a prepared, sterile bag of dialysate 813, through afirst external tube 814, external port C, second conduit 468, fifthintra-manifold port 448, first pump tube 456, first intra-manifold port440, first conduit 464, external port A, a second external tube 816, andinto dialysate reservoir 624. Dialysate can be heated and weighed indialysate reservoir 624 and then pumped using second peristaltic pump538 to the peritoneum of a patient through third external tube 818,external port E, eighth conduit 488, sixth intra-manifold port 450,second pump tube 458, second intra-manifold port 442, ninth conduit 490,second multivalve 492, tenth conduit 496, external port H, and fourthexternal tube 820. After a suitable dwell time, dialysate can be pumpedback to dialysate circuit 812 using fourth peristaltic pump 542 throughfourth external tube 820, external port H, tenth conduit 496, secondmultivalve 492, thirteenth conduit 504, third multivalve 500, twelfthconduit 502, first multivalve 478, sixth conduit 480, fourthintra-manifold port 446, fourth pump tube 462, eighth intra-manifoldport 454, seventh conduit 484, external port M, fifth external tube 822,and into drain bag 824. The dialysate can be weighed in drain bag 824before being pumped out and back to the manifold again using fourthdialysate pump 542, through fifth external tube 822, external port M,seventh conduit 484, eighth intra-manifold port 454, fourth pump tube462, fourth intra-manifold port 446, sixth conduit 480, first multivalve478, fifth conduit 476, external port J, sixth external tube 826, andinto a waste receptacle 828. A “last bag” 831, for example, holding adialysate having an alternative formulation to that used initially, canbe pumped into dialysate circuit 812 using second dialysate pump 538,through a seventh external tube 830, external port B, eleventh conduit498, third multivalve 500, thirteenth conduit 504, second multivalve492, ninth conduit 490, second intra-manifold port 442, second pump tube458, sixth intra-manifold port 450, eighth conduit 488, external port E,third external tube 818 and into dialysate reservoir 624. The dialysatecan then be heated and weighed before being pumped to the peritonealcavity, pumped back, and then drained in the manner described above forthe original dialysate cycled through dialysate circuit 812.

FIG. 10 is a schematic circuit diagram of a peritoneal dialysis system1010 in accordance with the present invention. FIG. 11 is a schematicflow diagram of peritoneal dialysis system 1010. Various componentsreferred to in this description of peritoneal dialysis system 1010 areshown in FIGS. 4-6 and discussed above, and the same reference numbersdepict the same features. Peritoneal dialysis system 1010 can beunderstood as a modification of hemodialysis system 610 shown in FIGS. 6and 7, and uses manifold 410 shown in FIG. 4. The “X's” shown in FIGS.10 and 11 show fluid paths from hemodialysis system 610, which are notutilized in system 1010. As peritoneal dialysis system 1010 is used forperitoneal dialysis with the peritoneum acting as the dialysis membrane,dialyzer 612 serves as a filter between the patient and dialysis circuit1012. Dialysate, for example, prepared dialysate from an externalsource, can be pumped using fourth peristaltic pump 542 through seventhexternal tube 648, external port J, fifth conduit 476, first multivalve478, sixth conduit 480, fourth intra-manifold port 446, fourth pump tube462, eighth intra-manifold port 454, seventh conduit 484, eighthexternal tube 650, sorbent cartridge 620, ninth external tube 654,ammonia sensor 658, tenth external tube 660, and dialysate reservoir624, then pumped using second peristaltic pump 538 through eleventhexternal tube 662, external port E, eighth conduit 488, sixthintra-manifold port 450, second pumping tube 458, second intra-manifoldport 442, ninth conduit 490, and second multivalve 492, where the flowis split between first and second flow paths 1014, 1016, respectively.First flow path 1014 passes through eleventh conduit 498, external portB, thirteenth external tube 668, and into dialyzer 612 through fourthdialyzer port 670. The second flow path passes through tenth conduit496, external port H, twelfth external tube 664, and into dialyzer 612through third dialyzer port 665. First and second flow paths 1014, 1016converge in dialyzer 612 and pass through the dialyzer, for example,semi-permeable membrane therein. The dialysate then passes throughsecond dialyzer port 636, through third external tube 634, external portG, fourth conduit 472, external port F, and to the peritoneum of patient611. After an appropriate dwell time, the dialysate is returned frompatient 611 to dialysate circuit 1012. The process is reversed and firstand second flow paths 1014, 1016 converge at third multivalve 500. Thedialysate then flows through twelfth conduit 502, and back to sixthconduit 480 to complete dialysate circuit 1012. Electrolytes can beadded to dialysate circuit 1012 from electrolyte source 618 using thirdperistaltic pump 540. Instead of splitting the dialysate flow, one offirst and second flow paths 1014, 1016, respectively, can be used whenpumping dialysate toward the peritoneum and the other of the two flowpaths can be used when pumping dialysate from the peritoneum. In somecases, the same flow path can be used in both directions. Alternatively,dialysate flow can be split in one direction, and not split in the otherdirection. By maintaining different flow paths for the two directions,contamination between used and regenerated dialysate can be minimized oravoided.

FIG. 12 is a schematic circuit view of a peritoneal dialysis system 1210in accordance with the present invention. FIG. 13 is a schematic flowdiagram of peritoneal dialysis system 1210. Various components referredto in this description of peritoneal dialysis system 1210 are shown inFIGS. 4-6 and discussed above, and the same reference numbers depict thesame features. Peritoneal dialysis system 1210 can be understood as amodification of hemodialysis system 610 shown in FIGS. 6 and 7, and usesmanifold 410 shown in FIG. 4. In peritoneal dialysis system 1210,extracorporeal blood circuit 626 shown in FIGS. 6 and 7 becomesperitoneum circuit 1226. An anti-coagulant source is not needed as bloodis not being circulated. Instead, a glucose source 1214, or otherosmotic agent source, can take the place of anti-coagulant source 614.While the flow paths of hemodialysis system 610 can remain unchanged inperitoneal dialysis system 1210, various modifications can be made, forexample, for sterility and anti-contamination purposes. For example, oneor more bacterial filters can be placed in twelfth external tube 664. Asecond dialyzer 1212 can be used as such a filter. Twelfth external tube664 can be replaced with a first branched tube 1216 and a secondbranched tube 1218. First branched tube 1216 can fluidly connectmanifold 410 at external port H to second dialyzer 1212. Second branchedtube 1218 can fluidly connect second dialyzer 1212 to third dialyzerport 665.

Dialysate for peritoneum circuit 1226 can be pumped in using firstdialysate pump 536 from a prepared dialysate source through externalport D and third conduit 470. Alternatively, or additionally, dialysatefor peritoneum circuit 1226 can be prepared by pumping in dialysateand/or water from dialysate source 622 (FIG. 6) using fourth peristalticpump 542 through seventh external tube 648, external port J, fifthconduit 476, sixth conduit 480, fourth pump tube 462, seventh conduit484, eighth external tube 650, sorbent cartridge 620, ninth externaltube 654, ammonia sensor 658, tenth external tube 660, and dialysatereservoir 624. Then, the dialysate can be pumped by second peristalticpump 538 through eleventh external tube 662, eighth conduit 488, secondpumping tube 458, ninth conduit 490, tenth conduit 496, and intodialyzer 612 through third and/or fourth dialyzer ports, 665, 670,respectively, wherein the dialysate passes through the membrane thereinand into peritoneum circuit 1226. Dialysate can be similarly preparedfor and retained in dialysate circuit 646. Continuous flow peritonealdialysis can then be performed with a first dialysate flowing throughperitoneum circuit 1226 to and from patient 611, and a second dialysatecirculating through dialysate circuit 646 serving to dialyze the firstdialysate across the membrane of dialyzer 612.

In peritoneal dialysis system 1210, the first dialysate can beperiodically weighed by draining off the second dialysate from dialysatecircuit 646 and flowing the first dialysate across the membrane ofdialyzer 612 from peritoneum circuit 1226 into dialysate circuit 646.This transfer can be performed to determine ultrafiltration and can beachieved by stopping first and second peristaltic pumps 536, 538,respectively, while continuing to pump with fourth dialysate pump 542 todeliver the first dialysate to dialysate reservoir 624 to be weighedusing scale 623. A difference between the initial weight of the firstdialysate infused into peritoneum circuit 1226, and the resulting firstdialysate, can be used as a determination of ultrafiltration. The firstdialysate can then be pumped back into peritoneum circuit 1226, anddialysate circuit 646 can be refilled with dialysate to provide a seconddialysate again. The dialysis process can then be restarted.

The present invention includes the followingaspects/embodiments/features in any order and/or in any combination:

1. The present invention relates to a method of performing peritonealdialysis comprising:

flowing dialysate along a first flow path through a manifold and into adialysate reservoir;

weighing the dialysate in the dialysate reservoir to obtain a firstweight;

flowing the dialysate out of the reservoir, along a second flow paththrough the manifold, and into a peritoneal cavity;

flowing the dialysate out of the peritoneal cavity, along a third flowpath through the manifold, and into a drain reservoir;

weighing the dialysate in the drain reservoir to obtain a second weight;and

flowing the dialysate out of the drain reservoir and along a fourth flowpath through the manifold.

2. The method of any preceding or following embodiment/feature/aspect,further comprising heating the dialysate in the dialysate reservoir.

3. The method of any preceding or following embodiment/feature/aspect,wherein the dialysate reservoir and the drain reservoir are weighedusing a common scale.

4. The method of any preceding or following embodiment/feature/aspect,further comprising determining the difference between the first weightand the second weight; and

determining at least one of ultrafiltration volume and ultrafiltrationrate based on the difference determined.

5. The method of any preceding or following embodiment/feature/aspect,wherein the manifold comprises at least four manifold conduits and eachflow path comprises at least one manifold conduit that is fluidlyisolated from the other three flow paths.

6. The method of any preceding or following embodiment/feature/aspect,wherein the manifold comprises at least two manifold conduits and atleast two of the four flow paths comprise a common one of the at leasttwo manifold conduits.

7. The method of any preceding or following embodiment/feature/aspect,wherein the dialysate is caused to flow by using at least one pump.

8. The method of any preceding or following embodiment/feature/aspect,wherein the at least one pump comprises at least one peristaltic pump.

9. The method of any preceding or following embodiment/feature/aspect,wherein the at least one pump comprises a first pump configured tocontrol dialysate flow in one of the flow paths, and a second pumpconfigured to control dialysate flow in a different one of the flowpaths.10. The method of any preceding or following embodiment/feature/aspect,wherein the at least one pump comprises a pump configured to controldialysate flow in more than one of the flow paths.11. The method of any preceding or following embodiment/feature/aspect,further comprising detecting for the presence of air in one or more ofthe flow paths.12. The method of any preceding or following embodiment/feature/aspect,further comprising measuring a pressure of the dialysate in at least oneof the second and third flow paths.13. The method of any preceding or following embodiment/feature/aspect,further comprising adjusting the flow of dialysate (1) into theperitoneal cavity, (2) out of the peritoneal cavity, or (3) both, tocontrol the dialysate pressure and keep it below a pre-determinedpressure.14. The method of any preceding or following embodiment/feature/aspect,wherein, after flowing the dialysate through the fourth flow path themethod is repeated starting with flowing a fresh supply of dialysatethrough the first flow path.15. The method of any preceding or following embodiment/feature/aspect,further comprising flowing a fresh supply of dialysate through a fifthflow path in the manifold, and into the dialysate reservoir, afterflowing the dialysate through the fourth flow path.16. The method of any preceding or following embodiment/feature/aspect,wherein the fresh supply of dialysate differs in composition from thedialysate flow into the dialysate reservoir.17. The method of any preceding or following embodiment/feature/aspect,further comprising engaging the manifold with a dialysis machineconfigured to carry out the method, forming a fluid communicationbetween the manifold and a supply of dialysate.18. The method of any preceding or following embodiment/feature/aspect,wherein the manifold comprises a first transom comprising a first edge,and second and third edges substantially parallel to the first edge,

a trunk substantially perpendicular and adjacent to the first transom,and

a second transom comprising a fourth edge, and fifth and sixth edgessubstantially parallel to the first, second, and third edges, whereinthe second transom is substantially perpendicular and adjacent to thetrunk and substantially parallel to the first transom.

19. A peritoneal dialysis system configured to perform the method of anypreceding or following embodiment/feature/aspect, the system comprising:

the manifold;

a dialysis machine in operable communication with the manifold andconfigured to flow the dialysate through the first, second, third, andfourth flow paths.

the dialysate reservoir in fluid communication with the manifold;

the drain reservoir in fluid communication with the manifold;

a scale configured to weigh at least one of the dialysate reservoir andthe drain reservoir; and

a heater configured to heat dialysate in the dialysate reservoir.

20. The method of any preceding or following embodiment/feature/aspectof performing peritoneal dialysis comprising:

flowing dialysate in a dialysate circuit through a first flow path, andinto a dialysate reservoir, the first flow path comprising a flow paththrough a manifold and through a sorbent cartridge;

flowing the dialysate out of the dialysate reservoir and through themanifold along a second flow path that differs from the first flow path;

flowing the dialysate from the second flow path across at least onefilter and into a peritoneum circuit;

flowing the dialysate through the peritoneum circuit and into aperitoneal cavity; maintaining the dialysate in the peritoneal cavity;

flowing the dialysate out of the peritoneal cavity, through theperitoneum circuit, across the filter and back into the dialysatecircuit; and

flowing the dialysate through the manifold along a third flow path andback into the dialysate reservoir, the third flow path comprising a flowpath through the sorbent cartridge.

21. The method of any preceding or following embodiment/feature/aspect,further comprising heating the dialysate in the dialysate reservoir.

22. The method of any preceding or following embodiment/feature/aspect,further comprising weighing the dialysate in the dialysate reservoir (1)before the dialysate is flowed to the peritoneum to obtain a firstweight (2) after the dialysate is returned to the dialysate reservoir toobtain a second weight, or (3) both.23. The method of any preceding or following embodiment/feature/aspect,wherein the weighing comprises (3), and the method further comprisesdetermining at least one of ultrafiltration volume and ultrafiltrationrate based on a difference between the second weight and the firstweight.24. The method of any preceding or following embodiment/feature/aspect,wherein the manifold comprises at least three manifold conduits, andeach flow path comprises at least one manifold conduit that is fluidlyisolated from the other three flow paths.25. The method of any preceding or following embodiment/feature/aspect,wherein the manifold comprises at least two manifold conduits and atleast two of the three flow paths comprises a common one of the manifoldconduits.26. The method of any preceding or following embodiment/feature/aspect,wherein the third flow path comprises at least one conduit that iscommon to both the first and second flow paths, and the first and secondflow paths comprise no conduit in common.27. The method of any preceding or following embodiment/feature/aspect,wherein the dialysate is flowed using at least one peristaltic pump.28. The method of any preceding or following embodiment/feature/aspect,wherein the at least one pump comprises a pump configured to controldialysate flow in more than one of the flow paths.29. The method of any preceding or following embodiment/feature/aspect,further comprising detecting the presence of air in at least one of theflow paths.30. The method of any preceding or following embodiment/feature/aspect,further comprising measuring a pressure of the dialysate in at least oneof the second and third flow paths.31. The method of any preceding or following embodiment/feature/aspect,further comprising adjusting the flow of dialysate (1) into theperitoneal cavity, (2) out of the peritoneal cavity, or (3) both, tocontrol the dialysate pressure and keep it below a pre-determinedpressure.32. The method of any preceding or following embodiment/feature/aspect,wherein, after returning the dialysate through the third flow path tothe dialysate reservoir, the method is repeated by flowing dialysatefrom the dialysate reservoir through the second flow path.33. The method of any preceding or following embodiment/feature/aspect,wherein the at least one filter comprises at least one dialyzer.34. The method of any preceding or following embodiment/feature/aspect,further comprising splitting the flow of dialysate in the second flowpath between at least two different branch lines before passing acrossthe flow in both branch lines the at least one filter.35. The method of any preceding or following embodiment/feature/aspect,further comprising engaging the manifold with a dialysis machineconfigured to carry out the method, and forming a fluid communicationbetween the manifold and a supply of dialysate.36. The method of any preceding or following embodiment/feature/aspect,wherein the manifold comprises a first transom comprising a first edge,and second and third edges substantially parallel to the first edge,

a trunk substantially perpendicular and adjacent to the first transom,and

a second transom comprising a fourth edge, and fifth and sixth edgessubstantially parallel to the first, second, and third edges, whereinthe second transom is substantially perpendicular and adjacent to thetrunk and substantially parallel to the first transom.

37. A peritoneal dialysis system configured to perform the method of anypreceding or following embodiment/feature/aspect, the system comprising:

the manifold;

a dialysis machine in operable communication with the manifold andconfigured to pump the first dialysate through the first flow path andconfigured to pump the second dialysate through the second and thirdflow paths;

the dialysate reservoir in fluid communication with the manifold;

the filter in fluid communication with the manifold;

the sorbent cartridge in fluid communication with the manifold;

a scale configured to weigh the dialysate reservoir; and

a heater configured to heat dialysate in the dialysate reservoir.

38. The method of any preceding or following embodiment/feature/aspectof performing peritoneal dialysis, comprising:

flowing a first dialysate in a peritoneum circuit along a first flowpath, the first flow path comprising a flow path through a manifold;

flowing a second dialysate in a regeneration circuit along a second flowpath and into a dialysate reservoir, the second flow path comprising aflow path through the manifold and through a sorbent cartridge;

flowing the second dialysate out of the dialysate reservoir along athird flow path through a first lumen of a dialyzer;

flowing the first dialysate through a second lumen of the dialyzer thatis separated from the first lumen by at least one semipermeablemembrane;

flowing the first dialysate into a peritoneal cavity;

maintaining the first dialysate in the peritoneal cavity, to form adialysate; and

flowing the dialysate out of the peritoneal cavity.

39. The method of any preceding or following embodiment/feature/aspect,further comprising heating the second dialysate in the dialysatereservoir.

40. The method of any preceding or following embodiment/feature/aspect,wherein the first and second dialysates are flowed using at least oneperistaltic pump.

41. The method of any preceding or following embodiment/feature/aspect,wherein the first dialysate is pumped along the first flow path using afirst pump, the second dialysate is pumped along the second flow pathusing a second pump, and the second dialysate is pumped along the thirdflow path using a third pump.42. The method of any preceding or following embodiment/feature/aspect,further comprising pumping electrolytes into the regeneration circuitusing a fourth pump.43. The method of any preceding or following embodiment/feature/aspect,further comprising detecting the presence of air in at least one of theflow paths.44. The method of any preceding or following embodiment/feature/aspect,further comprising measuring a pressure of the first dialysate in theperitoneum circuit.45. The method of any preceding or following embodiment/feature/aspect,further comprising adjusting the flow of the first dialysate (1) intothe peritoneal cavity, (2) out of the peritoneal cavity, or (3) both, tocontrol the dialysate pressure and keep it below a pre-determinedpressure.46. The method of any preceding or following embodiment/feature/aspect,further comprising flowing the first dialysate through the dialysatecircuit along a fourth flow path, and across the at least onesemipermeable membrane from the first lumen to the second lumen, andinto the peritoneum circuit, wherein the fourth flow path comprises aflow path through the sorbent cartridge and the manifold.47. The method of any preceding or following embodiment/feature/aspect,wherein the fourth flow path comprises at least one filter locatedbetween the manifold and the first lumen.48. The method of any preceding or following embodiment/feature/aspect,wherein the at least one filter comprises a second dialyzer.49. The method of any preceding or following embodiment/feature/aspect,further comprising:

draining the second dialysate from the regeneration circuit along afifth flow path;

flowing the first dialysate across the semipermeable membrane from thesecond lumen to the first lumen to transfer the first dialysate out ofthe peritoneum circuit and into the dialysate circuit along a sixth flowpath; and

measuring the weight of the first dialysate.

50. The method of any preceding or following embodiment/feature/aspect,further comprising comparing the first dialysate weight measured afterflowing the first dialysate out of the peritoneum circuit and intodialysate circuit, with an earlier measured weight of the firstdialysate, to determine at least one of an ultrafiltration volume and anultrafiltration rate.51. The method of any preceding or following embodiment/feature/aspect,further comprising flowing the first dialysate along a seventh flow pathback across the semipermeable membrane from the first lumen to thesecond lumen, out of the regeneration circuit, and into the peritoneumcircuit.52. The method of any preceding or following embodiment/feature/aspect,wherein the seventh flow path comprises a flow path through at least onefilter located between the manifold and the first lumen.53. The method of any preceding or following embodiment/feature/aspect,further comprising filling the regeneration circuit with dialysate toreform the second dialysate.54. The method of any preceding or following embodiment/feature/aspect,further comprising engaging the manifold with a dialysis machineconfigured to carry out the method.55. The method of any preceding or following embodiment/feature/aspect,wherein the manifold comprises:

a first transom comprising a first edge, and second and third edgessubstantially parallel to the first edge,

a trunk substantially perpendicular and adjacent to the first transom,and

a second transom comprising a fourth edge, and fifth and sixth edgessubstantially parallel to the first, second, and third edges, whereinthe second transom is substantially perpendicular and adjacent to thetrunk and substantially parallel to the first transom.

56. A peritoneal dialysis system configured to perform the method of anypreceding or following embodiment/feature/aspect, the system comprising:

the manifold;

a dialysis machine in operable communication with the manifold andconfigured to pump the first dialysate through the first flow path, andconfigured to pump the second dialysate through the second and thirdflow paths,

the dialysate reservoir in fluid communication with the manifold;

the filter in fluid communication with the manifold;

the sorbent cartridge in fluid communication with the manifold;

a scale configured to weigh the dialysate reservoir; and

a heater configured to heat dialysate in the dialysate reservoir.

The entire contents of all references cited in this disclosure areincorporated herein in their entireties, by reference. Further, when anamount, concentration, or other value or parameter is given as either arange, preferred range, or a list of upper preferable values and lowerpreferable values, this is to be understood as specifically disclosingall ranges formed from any pair of any upper range limit or preferredvalue and any lower range limit or preferred value, regardless ofwhether ranges are separately disclosed. Where a range of numericalvalues is recited herein, unless otherwise stated, the range is intendedto include the endpoints thereof, and all integers and fractions withinthe range. It is not intended that the scope of the invention be limitedto the specific values recited when defining a range.

Other embodiments of the present invention will be apparent to thoseskilled in the art from consideration of the present specification andpractice of the present invention disclosed herein. It is intended thatthe present specification and examples be considered as exemplary onlywith a true scope and spirit of the invention being indicated by thefollowing claims and equivalents thereof.

What is claimed is:
 1. A method of performing peritoneal dialysiscomprising: flowing dialysate along a first flow path through a manifoldand into a dialysate reservoir, the manifold comprising a manifold bodythat defines a plurality of internal passageways and a plurality ofports providing fluid communication to fluid passageways external to themanifold body, the manifold further comprising a first pumping tube, asecond pumping tube, and a third pumping tube each in fluidcommunication with the plurality of internal passageways, the pluralityof internal passageways partially defining each of the first flow path,a second flow path, a third flow path, and a fourth flow path, the firstflow path including the first pumping tube; weighing the dialysate inthe dialysate reservoir to obtain a first weight; flowing the dialysateout of the reservoir, along the second flow path through the manifold,and into a peritoneal cavity, the second flow path including the secondpumping tube; flowing the dialysate out of the peritoneal cavity, alongthe third flow path through the manifold, and into a drain reservoir,the third flow path including the third pumping tube; weighing thedialysate in the drain reservoir to obtain a second weight; and flowingthe dialysate out of the drain reservoir and along the fourth flow paththrough the manifold, the fourth path also including the third pumpingtube, wherein the flowing the dialysate along the third flow pathcomprises pumping the dialysate through the third pumping tube in afirst direction, and the flowing the dialysate along the fourth flowpath comprises pumping the dialysate through the third pumping tube in asecond direction that is opposite the first direction.
 2. The method ofclaim 1, further comprising heating the dialysate in the dialysatereservoir.
 3. The method of claim 1, wherein the dialysate reservoir andthe drain reservoir are weighed using a single scale.
 4. The method ofclaim 1, further comprising determining the difference between the firstweight and the second weight; and determining at least one ofultrafiltration volume and ultrafiltration rate based on the differencedetermined.
 5. The method of claim 1, wherein at least one of the first,second, third, and fourth flow paths is fluidly isolated from the otherthree flow paths.
 6. The method of claim 1, wherein the dialysate iscaused to flow by using at least one pump.
 7. The method of claim 6,wherein the at least one pump comprises at least one peristaltic pump.8. The method of claim 6, wherein the at least one pump comprises afirst pump configured to control dialysate flow in one of the flowpaths, and a second pump configured to control dialysate flow in adifferent one of the flow paths.
 9. The method of claim 6, wherein theat least one pump comprises a pump configured to control dialysate flowin more than one of the flow paths.
 10. The method of claim 1, furthercomprising detecting for the presence of air in one or more of the flowpaths.
 11. The method of claim 1, further comprising measuring apressure of the dialysate in at least one of the second and third flowpaths.
 12. The method of claim 11, further comprising adjusting the flowof dialysate (1) into the peritoneal cavity, (2) out of the peritonealcavity, or (3) both, to control the dialysate pressure and keep it belowa pre-determined pressure.
 13. The method of claim 1, wherein, afterflowing the dialysate through the fourth flow path, the method isrepeated starting with flowing a fresh supply of dialysate through thefirst flow path.
 14. The method of claim 1, wherein the plurality ofinternal passageways include a fifth flow path and the method furthercomprises flowing a fresh supply of dialysate through the fifth flowpath in the manifold, and into the dialysate reservoir, after flowingthe dialysate through the fourth flow path.
 15. The method of claim 14,wherein the fresh supply of dialysate differs in composition from thedialysate flow into the dialysate reservoir.
 16. The method of claim 1,further comprising engaging the manifold body with a dialysis machineconfigured to carry out the method, and forming a fluid communicationbetween the first flow path and a supply of dialysate.
 17. The method ofclaim 1, wherein the manifold body comprises a first transom comprisinga first edge, and second and third edges substantially parallel to thefirst edge, a trunk substantially perpendicular and adjacent to thefirst transom, and a second transom comprising a fourth edge, and fifthand sixth edges substantially parallel to the first, second, and thirdedges, wherein the second transom is substantially perpendicular andadjacent to the trunk and substantially parallel to the first transom.18. A peritoneal dialysis system configured to perform the method ofclaim 1, the system comprising: the manifold; a dialysis machine inoperable communication with the manifold and configured to flow thedialysate through the first, second, third, and fourth flow paths; thedialysate reservoir in fluid communication with the manifold; the drainreservoir in fluid communication with the manifold; a scale configuredto weigh at least one of the dialysate reservoir and the drainreservoir; and a heater configured to heat dialysate in the dialysatereservoir.
 19. The method of claim 1, wherein the manifold body furthercomprises a first pair of intra-manifold ports comprising respectivefirst and second intra-manifold ports that are connected to oppositeends of the first pumping tube, a second pair of intra-manifold portscomprising respective third and fourth intra-manifold ports that areconnected to opposite ends of the second pumping tube, and a third pairof intra-manifold ports comprising fifth and sixth intra-manifold portsthat are connected to opposite ends of the third pumping tube.